Battery chargers and their accompanying electrical components (e.g., cables and charge inlet) typically have current restrictions. To achieve more charging current for a battery charger (e.g., during a fast charge), large DC fast charge cables are usually required. Battery chargers also typically have a maximum limit in supply voltage. For example, SAE J1772 targets 900V and 400 A for the maximum output of a typical DC fast charger for electric vehicles. In order to increase the charging rate, the current-carrying capacity of electronics, components and leads typically need to be increased to handle larger currents, as does the heat removal capacity. For example, ohmic heating increases as the square of current. Accordingly, it would be advantageous to increase the charging rate without the need for larger current rated components.
In addition, battery operated devices (e.g., electric vehicles) typically use components (e.g., AC compressor, PTC heater, drive unit, etc.) that are designed to operate at a maximum voltage level. Battery operated devices also typically need to be able to operate while charging. Accordingly, it would be advantageous to increase the charging rate without increasing the voltage applied to the load of battery operated devices.
Battery systems also typically include more than one battery module. If a fault occurs in a battery module, the entire battery system likely needs to be disconnected from the load. Accordingly, it would be advantageous to manage a fault occurrence in a battery module without having to disconnect the load or cause a different voltage to be applied to the load.